1. Field of the Invention
The present invention relates to a tool driver, more particularly to an impact tool driver.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional impact tool driver is shown to include an elongated handle 1, a solid holding member 2, a compression spring 4, and a socket 205.
As illustrated, the handle 1 has an impact end 102 and a coupling end 103 opposite to the impact end 102, and defines a spring-receiving chamber 105 adjacent to the coupling end 103. The handle 1 is formed with a V-shaped cam hole 101 which is adjacent to the coupling end 103 and which is defined by a cam face 101W.
The solid holding member 2 has a mounting end 202 and a coupling end 203 opposite to the mounting end 202, and is formed with a pin hole 204 adjacent to the mounting end 202. The mounting end 202 of the solid holding member 2 extends into the spring-receiving chamber 105 in the handle 1 in such a manner that the pin hole 204 in the holding member 2 is registered with the cam hole 101 in the handle 1 in a radial direction of the handle 1. The socket 205 is mounted on the coupling end 203 of the holding member 2, and has a non-circular retention hole for receiving a tool bit or a workpiece (not shown).
The compression spring 4 is disposed within the spring-receiving chamber 105 in the handle 1, and abuts against the coupling end 202 of the holding member 2.
The pin 3 extends through the pin hole 204 in the holding member 2 and the cam hole 101 in the handle 1, and is in sliding contact with the cam face 101W in such a manner that the cam face 101W moves toward the coupling end 202 of the holding member 2 when an impact force is applied to the impact end 102 of the handle 1, which, in turn, drives the pin 3 together with the holding member 2 to rotate relative to the handle 1, thereby tightening or loosening the workpiece (not shown).
One disadvantage of the conventional impact tool driver resides in that the rigidity and strength of the handle 1 is weakened due to the formation of the spring-receiving chamber 105 and the cam hole 101 therein.
Therefore, the object of this invention is to provide an impact tool driver which includes a holding member formed with a spring-receiving chamber so as to overcome the aforesaid disadvantage of the prior art.
According to the present invention, an impact tool driver includes: an elongated handle including a solid and rigid shank that has an impact end and a coupling end opposite to the impact end, and that is formed with a V-shaped cam hole adjacent to the coupling end, the V-shaped cam hole being defined by a cam face; a hollow cylindrical holding member having an open end, a closed coupling end opposite to the open end, and a surrounding wall extending from the open end to the closed coupling end and defining a spring-receiving chamber accessible from the open end, the surrounding wall of the cylindrical holding member being formed with two diametrically disposed pin holes and being sleeved on the handle in such a manner that the coupling end of the handle and the cam hole are disposed in the spring-receiving chamber and that the pin holes in the cylindrical holding member are registered with the cam hole in the handle in a radial direction relative to the cylindrical holding member; a compression spring disposed within the spring-receiving chamber in the cylindrical holding member and abutting against the coupling end of the shank and the coupling end of the cylindrical holding member; and a pin extending through the pin holes in the surrounding wall of the cylindrical holding member and the cam hole in the handle, and in sliding contact with the cam face of the handle in such a manner that the cam face moves toward the closed coupling end of the cylindrical holding member against urging action of the compression spring when an impact force is applied to the impact end of the shank, thereby driving the pin to rotate, which, in turn, results in rotation of the cylindrical holding member relative to the handle.